Effect of selenium doping on structural and optical properties of SnS:Se thin films by electron beam evaporation method

SnS nanoparticle has been synthesized initially using SnCl2 center dot 2H(2)O and Na2S center dot XH2O, in the presence of TEA by precipitation method and XRD and FTIR techniques have been used for characterization of the sample. Powder X-ray diffraction studies revealed the particle size to be 48 nm and the pattern represents polycrystalline herzenbergite orthorhombic crystal structure of SnS. The FTIR result also confirmed the SnS at 2354 cm(-1). Secondly SnS:Se thin films have been deposited on glass substrates by electron beam evaporation technique and the films were annealed at 100 degrees C and 200 degrees C for 1 h. The unannealed films are amorphous in nature and the annealed film shows that a sharp crystalline peak is due to SnS. Also a peak is shown at 2 theta = 14.39 degrees, which is due to characteristic peak of SnSe2, established by their XRD patterns. The band gap energy (E-g) was determined from transmission spectra and an optical band gap of E-g varies from 1.6 eV to 1.79 eV.